This invention constitutes an improvement over U.S. Pat. Nos. 5,474,257 and 5,878,979 granted on Dec. 12, 1995, to Fisher et al, entitled Deployable Wing and Mar. 9, 1999, to Fisher et al, entitled Method and Apparatus for Landing a Wing, respectively. The patentees of these two patents are the same joint inventors of the invention covered in the above-captioned patent application and this application and these two patents are commonly assigned and both patents are incorporated herein by reference. These patents relate to deployable wings that are designed to carry a payload remote from the an air dropoff and for details of its construction reference should be made thereto. Suffice it to say that the common subject matter relates to deployable wing that comprises internal structure that is folded in a compact package that is airlifted by aircraft to an approximate destination and thereafter released and through the advent of sequentially operated parachutes is caused to deploy into a wing that is formed from a lower and upper delta shaped sail that is bounded at the edges to form an airfoil shaped enclosure. An opening at the forward center of the wing admits air to internally to fill the pocket defined by the lower and upper sails and expand the airfoil of the glider. The internal structure includes divergent leading edge spars attached to a central keel and a pair of diametrically opposed cross spars that when stored are folded into a relatively in-line or parallel position and when deployed the leading edge spars and cross spars extend perpendicular to the keel to form essentially a delta wing. Typically, after the glider is dropped from the aircraft parachutes are deployed and causes a slider to translate which, in turn, causes the cross spars that are pivotally attached to a sliding mechanism and each of the leading edge spars to translate and move angularly relative to the keel. The ram air then causes the wing to inflate, and once the glider is fully deployed these parachutes are disengaged from the wing and the glider begins its forward flight to its guided destination. The mechanism for performing these functions are detailed in U.S. Pat. No. 5,474,257 and for further details reference should be made thereto.
An internal heavier fabric is sewn to the lower sail and forms a portion thereof and extends to the upper sail and is sewn to define a protective pocket for the leading edge spars. A plurality of ribs formed from fabric is sewn to the upper sail and lower sail and extends from the forward to the aft end of the internal fabric. These ribs are equally spaced and extend across the cross spar. Obviously, a slot is formed in the ribs to allow the transition of the cross spar from the stored position to the deployed position, The length of the slots is sufficient to allow the cross spars to move the distance required to deploy the wing. The slot is say, approximately 12 inches and in the heretofore designs the slot remained unaltered and, hence, opened. Although the opened slot is internal, the effect of this opening causes bulges in the airfoil on the upper and lower sails adjacent to these openings when the wing is extended due to the external and internal air pressure acting on the wing. These bulges or protrusion in the sail are a source of drag and adversely affect the efficiency of the wing.
The purpose of the present invention is to solve this bulging problem and hence, alleviate a condition on the airfoil that adversely impacts the flight thereof. We have found that by employing a zipper and the mechanism for causing the zipper to close and eliminate the slot the problem of the opened slot is alleviated or at least minimized.